Misadventures in Bi-Amping

Lazarus Short

Lazarus Short

Veteran and General Yakker
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Independence, MO
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I'm the Red Knight, by grant of the Black
I tried biwiring a while back - no big improvement. Went back to single wire. Now, with all the amps I currently own, I decided to biamp. I already had this Yamaha DSP-A2070, and then scored a Yamaha A/V receiver at a sale the other day. There was wire enough, so the 100 wpc receiver for the highs, the DSP (80 wpc) for the lows - it has great bottom end. I set them both up to run off the Acoustat preamp.

Sound: a bit disjointed, not integrated top to bottom, a bit flat, distant, veiled. The A/V unit is a bit noisy, I have no way to know if the units are level-matched. So...it's back to single amp, single wire, either the Cyrus or the Luxman. End report.
 
Lazarus Short said:
I tried biwiring a while back - no big improvement. Went back to single wire. Now, with all the amps I currently own, I decided to biamp. I already had this Yamaha DSP-A2070, and then scored a Yamaha A/V receiver at a sale the other day. There was wire enough, so the 100 wpc receiver for the highs, the DSP (80 wpc) for the lows - it has great bottom end. I set them both up to run off the Acoustat preamp.

Sound: a bit disjointed, not integrated top to bottom, a bit flat, distant, veiled. The A/V unit is a bit noisy, I have no way to know if the units are level-matched. So...it's back to single amp, single wire, either the Cyrus or the Luxman. End report.
Click to expand...

Think about that- your woofers have large diameter voice coils around a large magnet. Big cone. Moves a large volume of air. This requires more current.
Tweeters/mids are much smaller diameter coils, move the cones/domes back and forth with a much smaller excursion. Current demand is less.

Use the higher wattage amp for the lows and the smaller wattage amp for the highs and see if there's a difference. (The difference you state is only 20watts, actually I don't expect there to be much difference, but just give it a shot for shits 'n' giggles...)
 
MarkWComer said:
Think about that- your woofers have large diameter voice coils around a large magnet. Big cone. Moves a large volume of air. This requires more current.
Tweeters/mids are much smaller diameter coils, move the cones/domes back and forth with a much smaller excursion. Current demand is less.

Use the higher wattage amp for the lows and the smaller wattage amp for the highs and see if there's a difference. (The difference you state is only 20watts, actually I don't expect there to be much difference, but just give it a shot for shits 'n' giggles...)
Click to expand...

I was aware of the wattage thing, and meant to use the Luxman A-007 (50 wpc) for the highs. It has a preamp out, and I can use the big Yamaha as a power amp. I still don't know how I would level-match. I think I will try that, however, so's I can avoid having the signal go through a pre and then an integrated.
 
I bi-wire with a good jumper cable (mids to highs) only to get rid of the jumper bars B&W supplies. There was a noticeable difference. System sounds good to my 60+ year old ears. I doubt if bi-amping would make a noticeable difference to my ears.
 
SUCCESS!!!
Well, I could have done this months ago - I set up the Luxman A-007 to use its internal DAC instead of the DAC in the Denon DVD player (I'll A/B those later), and to power the mids and highs. I connected the Luxman's pre-outs to the main-in inputs of the Yamaha DSP-A2070, to power the woofers. This eliminated a lot of circuitry, and I got to use only one volume pot, as the Yamaha is working as a power amp. Thus the 50 wpc of the Luxman adds to the 80 wpc of the Yamaha, and my ears can sense the increase in power. Everything I said about my previous attempt is reversed - the sound seems (to my ears) integrated from top to bottom, coherent, immediate, clear and crisp. I got to hear the B&W 802's the other day at a local audio salon ($21,000), so I may be just a bit critical of my system, but it does sound better. I've listened to Varttina and Radio Tarifa so far, and percussion is great.
 
Lazarus Short said:
SUCCESS!!!
Well, I could have done this months ago - I set up the Luxman A-007 to use its internal DAC instead of the DAC in the Denon DVD player (I'll A/B those later), and to power the mids and highs. I connected the Luxman's pre-outs to the main-in inputs of the Yamaha DSP-A2070, to power the woofers. This eliminated a lot of circuitry, and I got to use only one volume pot, as the Yamaha is working as a power amp. Thus the 50 wpc of the Luxman adds to the 80 wpc of the Yamaha, and my ears can sense the increase in power. Everything I said about my previous attempt is reversed - the sound seems (to my ears) integrated from top to bottom, coherent, immediate, clear and crisp. I got to hear the B&W 802's the other day at a local audio salon ($21,000), so I may be just a bit critical of my system, but it does sound better. I've listened to Varttina and Radio Tarifa so far, and percussion is great.
Click to expand...

Awesome. Glad to see you found a combo that works and that you hear the difference.
 
I'll be the first to admit I'm CHEAP, but then again I built many of my speakers.
 
orange said:
I'll be the first to admit I'm CHEAP, but then again I built many of my speakers.
Click to expand...

I'm cheap too, and the furthest I ever got up the B&W food chain were the Matrix 805's, used at an auction. I'm suspecting that the B&W wafflebacks in the shop system may well sound better on the top end than the Vandersteens. Another A/B comparison in my future...


 
Hi Laz.
Just found this thread. How is the Bi-amp system going? I was curious as to what crossover/divider network
you are using.
cheers
jM
 
JustMike said:
Hi Laz.
Just found this thread. How is the Bi-amp system going? I was curious as to what crossover/divider network
you are using.
cheers
jM
Click to expand...

Hey Mike, I just now stumbled onto my old thread, and saw your post. The wonder of this set-up is that I'm NOT using a crossover or divider network, except what's internal to the speakers. Those things are hard to find, and expen$ive when found. I need to run some frequency sweeps to make sure I've got the whole frequency spectrum, but it sounds good to my ears. How are things in mid-MO?


DD
 
OneTonScoutII said:
I'm fairly ignorant to Bi-amping but one would want to have a digital active cross over to utilize it to it's potential. correct?
Click to expand...

Active.... definitely. Digital.... typically a learning curve and computer interface. But, digital can be extremely flexible. Check out some of miniDSP units. Specifically the 2x4, 2x8 and 4x10. (2x4 may not have enough output)

https://www.minidsp.com/products/minidsp-in-a-box

Use their mic for calibration. Easier to find your starting point this way.

https://www.minidsp.com/products/acoustic-measurement/umik-1
 
I posted this on another thread a few days ago:

Well, I finally found one of the speaker widgets for the Nuvo amp, and hooked it up. I liked it at first, but paired with the JBL's and their titanium tweeters, it was hard on the ears. This amp is crisp to a fault, and leading-edge transients are hard, hard, HARD. Also, vocals tend to get drowned out by instruments. It was tested by the FYEO tech's at 70 wpc, and it sounds like it has more power than that, but hardly gets warm. I think I'll try it out for woofer duty on the Vandersteen's.

EDIT: Maybe the big surprise of the session was the preamp I used - a smallish Aiwa C30 which I picked up at a flea market with some other Aiwa gear for twenty bucks. I had not powered it up for years. It was clean, the volume pot was not scratchy and it sounded good. Too bad I have it promised to someone...

​


​


Today, I hooked up the Nuvo in place of the Yamaha, to power the woofer section of the Vandersteens, and let me tell you, this amp walks all over the two grand, DSP Yamaha! Bass is more articulate, and not by a little either, and the decay of notes is, well, notable. Even the non-bass sounds better, and I think it's a matter of being able to hear details formerly hidden by not-so-clean bass. I think that class-D amp will be in my system for a long time.
 
I have been thinking of bi or tri amping as well. I have a WOPL 1000, a stockish PL 400, and the internal amp in my SX-950.

My speakers are Ohm model Is, they are capable of bi-amping with a selector switch and two sets of binding posts per speaker.

However they currently sound fantastic with the single WOPL 1000. It is certainly loud enough, the only benefit I may gain is the cool factor of bi-amping.

Still trying to decide if I should go down the road or not.
 
Well, here I am a few months later. The NUVO got replaced by a Denon POA-2400A, but the rig was bass-heavy with 200 wpc to the woofers. Tonight, I put the Yamaha DSP amp back to woofer duty and inserted the Luxman A-007 for the mids & tweets. Fifty wpc for the Lux and 80 for the Yamaha, and things seems more balanced. The Denon's speaker terminals had broken, and were not in the best shape when I horse-traded for it. I'll need to listen to more music to decide if this will do...
 
Berhinger makes a great affordable digital crossover that has all the bells and whistles that you will ever need. around 300 bucks for it
 
Skratch said:
Berhinger makes a great affordable digital crossover that has all the bells and whistles that you will ever need. around 300 bucks for it
Click to expand...

Thanks - I'll check that out. So far, I'm getting a bit less bass slam, but better balance across the audio spectrum.
 
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